Retainer for percussive tools



A. JIMERSON RETAINER FOR PERCUSSIVE TOOLS Filed Oct. 2, 1922 P I INVENITOR v flaiwwfl-zfiracz'on 45 I forming a part hereof, in which- Patented Jan. 27, 1925.

UNITED STATES it 11,524,251 PATENT OFFICE;

FRANCIS A. JIMERSON, OF ATHENS, PENNSYLVANIA, ASSIGNO'R TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, -NEW JERSEY, A CORPORATION OF NEW JERSEY.

\RFJDAINER FOR PERCUSSIVE TOO-LS.

Application filed October 2, 1922.- Serial No. 591,735.

To all whom it may concern: I

Be it known that I, FRANCIS A. JIMER- SON, a citizen of the United States, and a resident of Athens, county of Bradford, and State of Pennsylvania, have'invented a certain Retainer for Percussive Tools, of which the following is a a specification accompanied by drawings.

This invention relates to tool retainers for percussive tools but more particularly to a retainer'of the type in which a sleeve or casing is adapted to be suitably held or -secured on the end of the percussive tool in position to be engaged by the implement sought to be retained within the percussive tool. r

In percussive tools used as coal picks, tie tampers, and the like, the working implement or steel is subjected to severe impact and various devices have been employed to cushion or yieldingly hold the retainer. In some of such devices the retainer is screwthreaded to the cylinder of the machine,

many of the devices including springs or other resilient metallic means as the sole or principal cushioning element, and breakage of the retainer or parts connected therewith is apt to occur.

Oneobject of the present invention is to simplify and improve the retainer construction and reduce the liability of breakage by more resiliently and effectively mounting or holding the retainer so that the movement of the retainer under the impact of the working implement or steel is effectively cushioned.

Another object of the present invention is to employ fluid pressure as the principal cushioning agent for resiliently holding the retainer against'the impact of the percussive or working implement With the above and other objects in view I have devised the retainer construction described in the following specification and shown in the accompanying drawings,

taken on the line 2-2 of Figure llooking in the direction of the arrows,

looking spring;

retainer sleeve L.

Figure 3 1s a plan view of the retainer" Figure l is a perspective view partly in section, of one of the retainer looking rings,

and Figure 5 is a side view of the front end of the machine showing the retainer as it pick, in which the tool cylinder A is provided with a bore B and a piston G is adapted to reciprocate in the bore B to actuate the percussive or working implement D, which may be a coal pick, tie tamper, core breaker, drill, or similar device.

The shank E of the implement D is removably supported within a hollow sleeve or bushing F whichis preferably pressed into or otherwise firmly secured Within the bore G at the forward end H of the cylinder A, the sleeve F having a flange J which abuts against the cylinder end H and extends slightly beyond the outer edges of the cylinder end H. The shank E of the steel may be either rounder hexagonal, as shown, and the collar K is adapted to engage the flange J to limit the extent to which the shank E extendswithin the forward end of the cylinder end H.

The retainer proper comprises a cylin-' drical sleeve L which is adapted to surround the forward end H of the c linde'r A, Y

retainer and also acts as a spacer between the outer wall of the cylinder end H and the inner wall of the retainer sleeve L,

thus leavin a spLace Q, at the forward end of the mac 'ne etween the forward ends of the sleeve J and retainer sleeve L affording a limited amount of; movement for the ercussive or working implement D. The ange J also serves as a stopfor limiting --the inward movement of the sleeve L. An

annular chamber R- is also formed between the forward end H of the cylinder and A resilient device, which maybe a coiled sprli1 'dS, located in the'chamber R, serves to o the retainerL against the flange or stop J. The spring Sis compressed between annular filling rings T at the opposite ends of the chamber R and -an annular locking ring U is inserted in the o n rearward end of the chamber R, this 100 ing rin ll preferably havin a beveled surface which is adapted to lie opposite a recess W in the innerwall of the retainer sleeve L so that a substantially circular split locking spring X may be inserted in the recess W and thus engage the beveled surface V so that the ring U will he held within the chamber R under the pressure-of the spring S. The end o'f the retainer sleeve L is cut away, as shown at Y, so that the straightends or fingers Z of the sprin X may be manipulated and pressed toget or to remove the spring from or insert it within the recess W, during the assembling or disassembling of the'retainer. 1 A fluid conveying passage a leads from any desired source within the ercussive' tool to the interior of the chamber and during the operation of vthe percussive tool this chamber is constantly under fluid pressure, which may be the same fluid admitted at the inlet (1 which operates the percussive tool, and which exerts pressure to cushion the retainer L against the impact of the blow administered by the collar K of the working implement D in its striking'movement under the influence of the blows of the reciprocat ing piston C. Packing rings b which are U- shaped in cross section between the filling ring T and flange J at one end of the chamber R and the filling ring T and locking ring U at the opposite end of the chamber R, serve to preve'ntthe escape of fluid pressure from the chamber R.

l The spring S does not appreciably cushion the retainer L, the'motive fluid pressure within the chamber R being depended upon as the principal cushioning agent. In the use of the present construction it is a practical impossibility for the cushioning means tobe completely collapsed, as when springs are employed, so that the retainer cannot strike orcilgly against a rigid part of the tool-or be itself rigidly held so that it could receive an uncushioned blow. Such disadvantageous conditions have resulted in breakage of retainers in the past, but are obviated in the present construction.

I claim: 1. -a percussive tool having a cylinder and a collared working implement adapted to extend into said cylinder, the combination of a bushing secured inthe bore of the cylinjder,'a flange on said bushing forming a sto 'for'limiting the inward movement of sai implement in said. cylinder, a cylindrical sleeve loosely. surrounding the front end "of said cylinder and provided with a holethrough which said implement extends, said collar on the working implement havin limitedmove'ment between said sleeve an said flange, pneumatic means for cushioning the movement of said sleeve in one direction,

spring means for holding said sleeve against said flange, an annular locking ring for closing one end of said sleeve, and means for locking said ring in place adapted to be readily removed to permit disassembly of movement of said sleeve in one direction, in-

eluding a pair of annular rings between said cylinder and sleeve, means for introducing pressure fluid between the cylinder and sleeve, and packing carried by said rings for preventing the escape of ressure fluid from the space between said cy 'nder and sleeve, a

islpring for holding said sleeve against said ange and seating at each end on one of said annular rings, and means for closing one ,end of said sleeve.

3. In a, percussive tool having a cylinder and a collared working implement adapted to extend into said cylinder, the combination "of a bushing secured in the bore of the cylinder, a flange on said bushing forming a stop for limiting the inward movement of said implement in said cylinder, a cylindrical sleeve loosely surrounding the front end of said cylinder. and provlded with a hole through which said implement extends, the

inward movement of said sleeve being limited by said flange, and said collar on the working implement having limited movement between said sleeve and said flange,

pneumatic means for cushioning the movement of said sleeve in one direction, in-

cluding. a pair of annular rings between said cylinder and sleeve, means for introducing pressure fluid between the cylinder and sleeve, and packing carried by said rings for preventing the escape of pressure fluid from the s cc between said cylinder and sleeve, a spring for holding said sleeve against said flange and seating at each end on one of said annular rings andan annular locking ring foi-iclosing one end. of said sleeve, a spring for locking said ring in place, and fi are on said springfor enabling said spring to be readily removed to permit disassembly of the parts.

In testimony whereof I have signed this specification. 4

FRANCIS a. JIMERSON. 

